NEW THIOAMIDE DERIVATIVE OR ITS SALT

PURPOSE:To provide a new thioamide derivative having squalene epoxidase- inhibiting activity and useful as an anticholesteric agent having high safety and free from the problems of the synthetic hindrance of other metabolite and the accumulation of harmful substance in the body. CONSTITUTION:The thioamide derivative of formula I (R is group of formula II or formula III; R is H or lower alkyl), its salt or their optically active compound, e.g. (E)-N-(6,6-dimethyl-2-hepten-4-ynyl)-N-ethyl-3-[[N-methyl-N-(3-thenyl) thiocarbamoyl]methoxy]benzylamine of formula IV. The compound can be produced by reacting a compound of formula I' with equimolar or excess amount of a sulfurizing agent such as P2S5 or Lawsson's reagent at room temperature or under heating, preferably under heating. Since the compound has squalene epoxidase-inhibiting activity, it is useful for the treatment or prevention of various diseases caused by the action of cholesterol such as arteriosclerosis.